Metal removing tool



Dec. 16', 1947. w. V.1. BLAZEK 2,432,855

Filed Jan. 28, 1944 4 sheets-sheet 2 INVENTOR. WILLIAM J, BLAZEK.

- Dec. 16, 1947. w, J BLAZE-K 2,432,855

' METAL REMOVING TOOL v Filed Jan; 28;- 1944 4 Sheets-Sheet-S MWL Dec. 16, 1947. w. J. BLAzl-:K l 2,432,855

' METAL REMOVNG TOOL Filed Jan. 2s, 1944 4 sheets-sheet 4 WILLIAM J. BLAZEK.

IN VENT OR.

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Patented Dec. 16,1947

METAL REMOVING TOOL William J. Blazek, Cleveland Heights, Ohio, as-

signor to Lempco Products, Inc., Bedford, Ohio. a corporation of Ohio Application January 28, 1944, Serial No. 520,037

(c1. 'zi- 755) 6 Claims.

This invention relates, as indicated, to metal removing tools, but has reference more particularly to reamers and hones of the expansion type.

Tools of the aforesaid type, in accordance with the prior art, comprise a mandrel and two or more segments, each having a plurality of cutting edges, the segments being mounted on the mandrel in such a manner as to be expansible in relation to the mandrel. All of the cutting edges, whether the tool be a reamer or a hone, lie on the periphery of a circle or cylinder, with each segment forming an arc of the circle or a part of the cylinder. If, in such an expansion tool, the segments simply move outwardly or radially from the mandrel, then only the central portin of the cutting edges or surface of each segment is effective to remove metal. This follows from the geometric truth or axiom that a smaller or circumscribed circle, i. e., that formed by the cutting edges or surfaces of the segments, can be tangent to a larger or circumscribing circle, i. e., that formed by the bore or opening which is being rearned or honed, at but one point.

This removal of metal by only the central portions of the segments is highly objectionable because, in the case of a reamer, such portions become dulled, while the remaining portions of the cutting surfaces remain sharp. In the case of a hone, such central portions tend to become loaded while the remaining areas of the honing surfaces remain unloaded. Thus, in the case of a tool consisting of three segments, only about one third of the effective cutting edges or surfaces are utilized. f

It has been proposed, as in Evans Patent No. 1,902,062, to utilize more than merely the central portions of the cutting surfaces of the segments by providing means consisting of segment-supporting surfaces which extend across the axis of the mandrel, but I have found that the manufacture of reamers in accordance with the patent is not only expensive, but extremely difficult from the machining and inspection standpoints.

The present invention, accordingly, has as its primary object the provision in cutting tools of the character described of new and improved means for utilizing more than the central portions of the cutting surfaces of the segments.

Another object of the invention is to provide means of the character described, which are economical and easy to machine and which can vbe easily and accurately inspected.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims; the annexed drawings and the following description setting forth in detail certain structures embodying the invention, such disclosed structures constituting, however, but a. few of the various structural forms in which the principle of the invention may be used.

In said annexed drawings:

Fig. 1 is an elevation of an expansion reamer having incorporated therein the principal features of the invention;

Fig. 2 is a longitudinal cross-sectional View of the reamer shown in Fig. 1, in the unexpanded condition;

Fig. 3 is a View similar to Fig. 2, but showing the reamer in the substantially fully-expanded condition;

Fig. 4 is an end elevation of-one of the reamer segments;

Fig. 5 is an elevation of the bottom face of one of the reamer segments;

Fig. 6 is a cross-sectional view, taken on the line 6-6 of Fig. 1, but with the cutting teeth of the reamer segments not shown in cross-section;

Fig. 7 is a view similar to Fig. 6, taken on the line 'I-l of Fig. 3;

Figs. 8 and 9 are views illustrating in a more or less diagrammatic manner steps in the making of the reamer segments shown in Fig. 1;

Fig, 10 is a cross-sectional view of a hone segment similar to the reamer segments shown in Figs. 1 to 9 inclusive;

Figs. 11 and 12 are views similar to Figs. 8 and 9, but illustrating a modified method of forming the reamer segments;

Figs. 13 and 14 are views similar to Figs. 6 and '7, respectively, but utilizing the reamer segment of Figs. 1l and 12;

Figs. 15, 16 and 17 are views corresponding to Figs. 1, 2 and 3 respectively, but of a somewhat modified form of theinvention;

Fig. 18 is an elevation of the bottom face of one of the reamer segments shown in Fig. 15;

Fig. 19 is a cross-sectional View, taken on the line IS-IS of Fig. 15;

Fig. 20 is a cross-sectional View, taken on the line 20--20 of Fig. 17;

Fig, 21 is a cross-sectional view of a hone segment similar to the reamer segments of Figs. 15 to 20 inclusive;

Figs. 22 and 23 are views similar to Figs. 2 and 3 respectively, but showing a further modification of the invention;

Fig. 24 is an end elevation'of one of the reamer 3 segments of the form of reamer shown in Figs. 22 and. 23;

Fig. 25 is an elevation of the bottom face of the reamer segment of Fig. 24;

Fig. 26 is a cross-sectional view, taken on the line 26-26 of Fig. 22;

Fig. 27 is a cross-sectional View, taken on the line 21-21 of Fig. 23, and

Fig. 28 is a cross-sectional view of a hone segment similar to the reamer segments Shown in Figs. 22 to 27 inclusive.

Referring more particularly to Figs. l to 9 inclusive of the drawings, it will be seen that an expansible reamer made in accordance with the invention comprises a mandrel I, which for a portion of its length is cut or milled to provide flat bearing surfaces 2, 3 and 4, which are'tapered or inclined to the axis O of the mandrel. As shown in Figs. 6 and 7, a transverse section through the mandrel which intersects these surfaces will be inthe form of'. an equilateral triangle, the sides ofl which form chords ofv a circle, which is representedby thedotted lines in Fig. 6, and the center of whichv is the center O of the mandrel.y

Each of the'surfaces 2, 3 and 4 is provided with a track or segment guide 5, which, as clearly shown in Figs. 2 and 3, extends longitudinally and the base thereof is substantially centrally of the surface 2, 3 or 4, as the case may be, and is laterally inclined to, provide a leading surface 6 which is disposed at an acuteangle to the surface 2, 3 orv 4and a trailing surface 'I which is disposed at an obtuse angle to the surface 2, 3` or 4. As shown most clearly in Fig. 2, the outer edges of the surfaces 6 and 1 are parallel with lines A-A which lie in the surfaces 2', 3 and'llY and represent the intersection ofA such surfaces by radialv planes extending from the center O and at rig-ht angles to the surfaces 2, 3 and 4. It may be noted at this point that the tracks extend longitudinally ofthe mandrel and substantially centrally of the surfaces 2, 3 and 4, in contradistinction to the surfaces 3| and 32`in Evans Patent No. 1,902,062, which slant across the axisof the mandrel.

Mounted' on' the tracks 5 are metal cutting segments 8, Which'collectivelyform areamer, each segment being generally cylindriformand'spirallylutjed' toformv a plurality ofreamer teeth 9, as shownV in Figs. 1V and 4, the' cross-section ofv such teeth being omitted' from Figs.' 6' and '7 in order topermit a clearer descriptionv of the' cutting action` of the reamer inthe unexpanded and expanded condition, it being understood that the direction of rotation of the' reamer is indicated by' the arrows in Figs. Gand 7. If desired, the cutting teeth on one segment may be spiralled oppositely from the spiralling'ofI the'cutting teeth ofy another segment, as described in-theaforesaid Evans patent.

As'shown in Figs. 4, 5, 6 and 7, each of the segments is provided on its under surface or base with a longitudinally'extending recess or keyway I0 having sidewalls II and I2Y which are inclined to correspond with theinclination-of thesurfaces 6? andV 'I respectively ofl the tracks 5; With the segments m-ounted on the tracks, as shown in Fig. 6', the surfaces 6 of the tracks Sengagethe side walls II of the segments andvin this manner not only` insure a positive drive of the segments when the mandrelis rotated in thedirection indicated by the arrow, but also provide a cam action which tends to holdrthe segments firmlyv against the mandrel.

In order to insure parallelism ofthe cutting surfaces off the.` segments withk the.y axis-of.'v thev mandrei, the segments are tapered longitudinally, as shown in Figs. 2 and 3, to conform with the taper or inclination of the surfaces 2, 3 and 4 of the mandrel.

The segments, moreover are beveled at the ends, as at I3, and are clamped between slidable collars I4 and I5. The collar I4 is positioned on the mandrel by means of an adjustingnut or sleeve IEil which is internally-threaded for engagement with a threaded portion II of the mandrel. One end of the sleeve I6 is provided with flats I8 for engagement by a wrench, whereby the sleeve may be rotated to adjust the position of the collar I4. The collar I5 is urged towards the collar I4 by means of a spring |29 which bears against a stop sleeve 2'9" which is pinned to the mandrel as by a, pin 2I- and is provided with flats, not shown, for engagement by a wrench or other tool, whereby the mandrel may be rotated or driven in the direction indicated by the arrow in Fig. 1.

The expansion of the segments of the reamer, as thus described, is effected by rotation of the nut or sleeve I6 while the reamer, as a whole, is maintained stationary. This results in a combined axial and radial movement of the segments against the tension of the spring I9', from a position, as shown for example in Fig..2, to a position, as shown for example in Fig. 3.

The cylindriform contours of the cutting seg ments, be they truly circular, elliptical, parabolic, or otherwise, are generated, respectively, about an axis which represents the center or average axis of convergence ofl radial planes produced through the generating lines of each of the cylindriform surfaces. Since the cylindriform surfaces areV circumscribed by the cylinder represented by the internalcircumference of the Work, they must be' scribed from lesser radii, requiringv that the generating or average axis of each of the segments falls on the side of the mandrel axis near'- est the segment regarded, and parallel thereto. And sinceitis desired to have the cutting segment engage the work in its trailing portions, the generating or average axis of the cylindriform segmentsv each shouldfall upon the trailing side of the segment with respect to a radial plane of the revolutionary axis of the mandrel which passes through the longitudinal axis of the tracks 5 at said mandrel. This may be regarded as the median plane of each segment.

It follows from this that at the minimum diameter for which the reamer is intended, and which isl represented by the bore 25 in Fig. 6, only the trailing portion 24 of the cutting surface of each segment, which portion isy approximately indicated by the bracket 26 in Fig. 6, is effective to remove metal fromthe bore, and that at the'maximum diameter for which the reamer is intended', andwhichis represented by the-bore 25min Fig. 7, only the central portiony ofv the cutting surface of eachV segment, which portion is approximately indicated by the bracket 21 in' Fig. 7, is effective to remove metal from the. bore. It also follows that asfthe tool is expanded, the portion of the cuttingv surfaceof each segment which is effective to'remove metal shifts from the trailing edge 24 towards the leadingV edge 23.

Ther leading edges 23 ofy the segments can be located closer to themandrel axisthanthe trailing edges, that isto say, theA proper' eccentricity of cylindriform curvature may be imparted thereto, by Various.A methods, one of which is diagramma-tically represented in Figs. 8 and 9. According tol-this method, segments having longitudinally extending recesses' IIlfa'nd cuttlngsurfaces of truly arcuate contour, are mounted upon a dummy mandrel, having tracks represented by the dotted lines in Fig. 8, such tracks being displaced from the position of the tracks of a mandrel such as shown in Fig. 6 suiciently to position the cutting surfaces of the segments eccentrically to the axis of the dummy mandrel. Then, by rotating the dummy mandrel about its axis and against a grinding or cutting Wheel or other cutting tool, portions of the segments diagrammatil cally illustrated by the shaded area 8a. in Fig. 8 are removed. When such segments are then mounted on a working mandrel as shown in Fig. 9, which corresponds with Fig..6, the leading edges 23 of the segments will be located closer to the axis O of the mandrel than the trailing edges.

It will thus be apparent that all of the advantages inherent in the expansible reamer of the Evans patent are obtained in the reamer as described, but that most, if not all, of the disadvantages have been eliminated, since it is considerably easier and less expensive to form or machine the tracks and recesses in the mandrel and segments respectively when they extend parallel With the generating lines of the conical or tapered portions of the mandrel than when at an angle to such lines. Moreover, it is much easier to gauge or accurately inspect the reamer than it is in the case of a reamer made in accordance with the Evans patent.

The tracks 5 need not necessarily be formed integrally with the mandrel, but may consist of separate elements which may be removably secured to the surfaces 2, 3 and 4 of the mandrel, and thus easily replaced in the event that they wear out. Moreover, the track need not form a part of or be attached to the mandrel, but may form an integral part of or be attached to the segments, in which event, the recesses wo-uld be formed in the surfaces 2, 3 and 4 of the mandrel, instead of in the segments. If desired, a separate key might be used, in which case, both the mandrel surfaces 2, 3 and 4 and the bottom surfaces of the segments would be recessed to accommodate such a key.

The invention is applicable as well to hones and other metal removing and nishing tools as it is to reamers.

Referring to Fig. 10 of the drawings, a hone segment is shown which is made interchangeable with the reamer segments shown in Figs. 1 to 9 inclusive. The hone or honing segment preferably consists of a. body portion 28 formed or molded of honing stone and mounted on a metallic backing 29, the composite structure being substantially identical in cross-section with the reamer segment of Fig. 1. Since the reamer and hone segments are interchangeable, it is only necessary, in order to convert the reamer of Fig. l into a hone, to remove the reamer segments and insert the hone segments.

Although the reamer which has been described comprises three segments, it will be understood that any desired number of segments may be used. It will be further understood that each segment has more than one cutting edge, the term cutting edge being used herein in a broad sense to include not only the reamer teeth but the cutting particles of a hone as well as any other form of metal removing edge.

Referring to that form of the invention sho-wn in. Figs. 11, 12, 13 and 14, the segments, in this case, have truly arcuate cutting surfaces 30, but the bottom surface 3| of each segment is so formed that itwill not `be parallel with the chord V32 of the surface 30. This is accomplished by removing that portion 33 of the segment which is indicated by the shaded area in Fig. 11. After the segment is thus formed, a longitudinal recess, as indicated in Fig. 12, is cut in the base of the segment, the bottom face 34 of such recess being parallel With the surface 3 I.

When the segments, as thus formed, are mounted on a mandrel, as shown in Fig. 13, the leading edges 35 of the cutting surfaces 3i) are disposed closer to the axis of the mandrel than the trailing edges 3E, with the result that in the unexpanded condition of the reamer, shown in Fig. 13, only the trailing portions of the cutting surfaces, indicated by the bracket 31, is effective to remove metal from the bore 25. In the fully expanded condition of the reamer, as shown in Fig. 14, only the central portion of the cutting surface, indicated by the brackets 38, is effective to remove metal from the bore 25a. Here again, it will be apparent that as the tool is expanded, the portion ofA the cutting surface of each segment which is effective to remove metal shifts from the trailing edge 35 towards the leading edge 35.

Although a hone segment corresponding to the reamer segment of Figs. 11, 12, 13 and 14 has not been illustrated, it will be understood that such a hone can be readily made in a manner similar to the construction of the hone segment shown in Fig. 10.

In that form of the invention shown in Figs. l5 to- 20 inclusive, the construction is considerably simplified by extending the tracks 5', corresponcling to the tracks of that form of the invention shown in Fig. 6, laterally to the trailing edges of the surfaces 2', 3' and 4', which correspond with the surfaces 2, 3 and 4 respectively, and by elimination of those portions of the base of the segments shown in Fig. 6; which are disposed to the trailing side of the inclined side wall or edge l2.

In this Way, machining costs are reduced, but the same results are obtained with the reamer, since the drive or rotation of the reamer segments is effected in the same manner as in Fig. 6, that is by interengagement of the inclined edges 6' of the mandrel with the correspondingly inclined edges Il' of the segments. The segments are beveled at their ends, as at I3.

The segments may be formed in the manner shown in Figs. 8 and 9 or in the manner shown in Figs. 11 and 12. In either case, the leading edges 39 of the cutting surfaces 40 are disposed closer to the axis of the mandrel than the trailing edges 4l, with the result that in the unexpanded condition of the reamer shown in Fig. 19, trailing portions of the cutting surfaces, indicated by the bracket 42, are eiective to remove metal from the bore 25. In the fully expanded condition of the reamer, shown in Fig. 20, only the central portion of the cutting surface, indicated by the brackets 43, is eifective to remove metal from the bore 25a. As the tool is expanded, the portion of the cutting surface of each segment which is elfective to remove metal'shifts from the trailing edge 4l towards the leading edge 39.

Referring to Fig. 21 of the drawings, a hone segment is shown which is made interchangeable with the reamer segments shown in Figs. 15 to 20 inclusive, and consists of a body portion 44 formed or molded of honing stone and mounted on a metallic backing 45. the composite structure being substantially identical in cross-section with the reamer segment of Fig. 15.

.ramasse Iof. the :mandreL: so that` the'.l walls 'lll form: with Lthesperiphery ofthe mandrel hook-:like portions, fasY shownk in Fig;r 26.

The edgesv- S9-oi thesehookelike'portions extend llongitudinally zof the'man'drel, .but are inclined 4Lto theaxis thereof. .Moreover, they may .be con- `sidered as' .ilines which? represent the :intersection foffttheftperiphery of the tapered portion ofthe iman'd'rel'.by"-radial'planes drawnv from the axis of'thel mandrel.

.The'f reamer segments wwhich are employed "in e connection with such=mandrel areshown in' Figs. V24'andi25, and are longitudinally tapered'as lsho'wn'l'in' Fig. 22 to2 correspond with the taperoi the inclination. ofzthe edges 49. Moreover; each segment has a cutting surface 50, which is oftruly arcuate formgandehas ahook-like. lange 5l at one `edge having an inner surface' 52'which is enl`gaged by the edgeA 49, theopposite edge 53 resting `fon 'the' peripheryof` the'. taperedportion of; the

mandrel.

The cutting surfaces of the segment-saire cut'to :a diameterwhichisfequal to or slightly less than the minimum diameter for which the tool'is intended and the vsegments/are mounted upon the mandrel. segments, onlyvthe' central portions ofthe cutting f surfaces of thei'segments-,vindicated bythe bracket 54 in Fig,26,Y are eiective to remove metal from sthebore-f25. :As the-tool is expanded, the trailing for.v rearportions 'of the -segments move radially outwardly'to a slightiy ygreater extentthan dothe leading or forward portions thereof, so'thatin -the fully expanded condition,` shown in-Fig: 27, the trailing portions-=oicthe cutting surfacesof the segments, indicated bylthei-br-acketf'are-effective @to lremove metal Afrom the bore 25a. In this v case, the :shift of lthe eiiective cutting portionof thev vcutting* surfaces tof.v the segments Ais :the reverse-of that inthefpreviously,described'forms of the invention. In Votherwords,as thetoolis-expanded, the portion of the cutting surf-ace of'each segmentwhichisr effective to remove'metal shifts y from the leading edgetowards the-trailing-edge'of Athe cutting surface.

lReferring to Figf 28 ofi the drawings; ahone segment is shown whichismadeinterchangeable with the reamervsegments shown in Figs; '22 to' 27 inclusive,l and consistsot abodyfportion 56 formed or-molded of honing stone and mounted on a metallicibacking'El, the:compositestructure being f substantially identical' in cross-sectionf-wththe reamersegment oFigr24.

It is mbe-'understood that `thevforms, loffmyy invention, :herewith shown and describedfare to be taken as preferred examples ofthe samegandth'at various changes' in the shape; vsize-and arrangement of partsmay fberesortedto, withoutdeparting from the spirit ofmyinvention-f or 4thescope v of the subjoined claims.

Having thus :described V'my ainvention, I- claim: .-.l.-An internal cutting tool'oi the eXpansible type comprising a-revolulclel mandrel forinsertion within the starting-bore ofl aflhollowsworkpieceto 'be acteduponpthe'axis-offrevolutionofsaid mandrel and the longitudinalzaxisoffsaid'borebeing In the unexpanded conditionv of the.;`

i8 fsubstantially: coincident when said vmandrelis lin voperativez'position.therein;;.a plurality of: cutting segments carried: by saidv mandrel for: rotation thereby,'fsaid: cutting segments having ygenerally 5 .':cylindriformY iWork-surfaces f disposed `about said tmandrel-'softhat' the generating. lines of saidy work vsurfaces lie:substantially:parallel: to the axiseof isaidtmiandrelfxandsothat theradial planes of f their: generating :lines respectively converge about 10 v'-f'ixesithat" are parallel to .thevk axis ofthe mandrel :butfoiL-setltherefromzin. directions' ofthe trailing f edge .ofeeach'.ofzJsaid-.segments. respectively; and Imeans:l'for"iexpa1:iding .said. .segments 1 by moving tthemlinspaths the longitudinali axes of whichilie ewholly; `within .the'radial planesfof. .the .fmandrels axis.

52.7.?An :internal cutting: tool. of. the. expansible fStypevcompr-ising: a revolublel mandrel,1a plurality f of cuttingssegments carried. byvsaidimandrek for --rotation thereby, nthe 'working surfaces vof said 'cuttings segmentsvk being..zgenerallyI cylindriform, ffandbeing disposedabout-and secured for relative Nmoti'on'lto. said mandrel; the axes about which said f. cyliridriformworking.surfaces are generated being gmarallel. to andeccentrically disposed relative to the lrevolutionary.'axisof the` mandrel,` and means forlmovingfsaid.segments instraight lines (which lcollectively:definefgeneratrices of a frusto-cone) axially'of the Amandrelto effect the vexpansion thereof relative to each other.

.:.3.-'4An.internalcutting tool of the -expansible Ytypefcomprisingfahrevoluble mandrel having a taperedA .portion intermediate its ends, Y straight `tr-ackways extending along, said tapered portion T for.' engaging cutting-segments, the long axis of eachttrackway :lying within' a radial plane of the revolutionaryaxis `of ,said mandrel, a plurality sof cutting segments'. disposed about said mandrel :.:in'associationwith said trackways, said segments 40. havingzgenerally Lcylindriform Work surfaces, the

v axes about'. which said Asurfaces are generated being. parallel toztherevolutionary axis of said man- I-drel but 4eccentrically disposed in relation thereto inthatftheaxis of each segment falls on the near side (with respect to the segment)' of the manfi'drels axis `and' upon the trailing side (with respect z .tothe direction of. revolution of the mandrel) of the radial plane of the mandrels axis which pro- ,g 4jectssthroughthe long .axis'of its associatedtracl:

i-Way.

:4in-metal removing vtool comprising a tapered mandrel"circularfin" crossl'section; a metal refrnovingfsegment'extending longitudinally along Lthea'mandreland' being slidable along the manl drel; 'means forming a-pivotalfdriving connection between thelmandrel and a longitudinal edge portion of 'thersegmenu the surfacel of the segment i facing the-mandrel 'being-concave relative to the .mandrel and the otherlongitudinal edge 4portion G01 ofxtheseg-ment engagingthe mandrel 'whereby the segment may pivot about said pivotal connection :asi thevsegmentiSmoved longitudinally on" the o mandrel;l and means for sliding the segment along :themandrel'iand fortiurging' thesegment in en- 651" gagement 'with'the mandrel.

lvA'rmetal removing. tool comprising a tapered :'imandrel circular in' cross section; a metal re- :movingI segment extending longitudinally along vthefrharidrel-andbeing slidable alongthe mandrel, said segrner'it-v carrying a metal removing surface having a contourvof less radius than the minimum` radius of the diameter of the work ',.piece-to beengaged by the segment; means form- !izing' arpivotali'diiving connection betweenthe lL-mandrel 'and `the 'longitudinal "edge portion lof the segment, the surface of the segment facing the mandrel being concave relative to the man.. drel and the other longitudinal edge portion of the segment engaging the mandrel whereby the segment may pivot about said connection as the segment is moved longitudinally on the mandrel for causing the metal engaging surface of the segment to engage different surfaces of the work piece as the effective diameter of the tool is varied; and means for sliding the segment along the mandrel and for urging the segment in engagement with the mandrel.

6. A metal removing tool comprising a mandrel having a tapered portion circular` in cross section; a longitudinally extending slot in said portion of the mandrel, the plane of one surface of said slot being angular with respect to the radial plane of said portion for forming an acute angular edge with the periphery of the mandrel; a metal cutting segment adapted to be carried by the mandrel; said segment having a projection along its leading edge extending loosely in the slot and engaged by said acute edge for forming a pivotal driving connection between the mandrel and segment, the surface of said segment 10 adjacent to the mandrel being concave whereby said segment is out of engagement with the mandrel intermediate the leading and trailing edges of the segment; and means for sliding the segment along the mandrel and for urging the segment in engagement with the mandrel.

WILLIAM J. BLAZEK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

